Cyber Posture

CVE-2025-21238

High

Published: 14 January 2025

Published
14 January 2025
Modified
24 January 2025
KEV Added
Patch
CVSS Score 8.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS Score 0.0067 71.4th percentile
Risk Priority 18 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2025-21238 is a high-severity Heap-based Buffer Overflow (CWE-122) vulnerability in Microsoft Windows 10 1507. Its CVSS base score is 8.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation of Remote Services (T1210); ranked in the top 28.6% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified are NIST 800-53 SI-2 (Flaw Remediation) and CM-7 (Least Functionality).

Threat & Defense at a Glance

What attackers do: exploitation maps to Exploitation of Remote Services (T1210) and 1 other technique. What defenders deploy: see the NIST 800-53 controls recommended below.
Threat & Defense Details

Mitigating Controls (NIST 800-53 r5)AI

prevent

Directly mandates timely identification, reporting, and correction of flaws such as CVE-2025-21238 via patching to prevent remote code execution in Windows Telephony Service.

prevent

Restricts the system to least functionality by disabling or limiting the non-essential Windows Telephony Service, reducing exposure to this RCE vulnerability.

prevent

Enforces memory protections like ASLR and DEP to mitigate stack-based buffer overflow (CWE-122) exploitation leading to RCE in the telephony service.

MITRE ATT&CK Enterprise TechniquesAI

T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
T1059 Command and Scripting Interpreter Execution
Adversaries may abuse command and script interpreters to execute commands, scripts, or binaries.
Why these techniques?

RCE in Windows Telephony Service with AV:N allows direct exploitation of a remote service (T1210) resulting in arbitrary command execution (T1059).

Confidence: HIGH · MITRE ATT&CK Enterprise v18.1

NVD Description

Windows Telephony Service Remote Code Execution Vulnerability

Deeper analysisAI

CVE-2025-21238 is a Remote Code Execution vulnerability affecting the Windows Telephony Service. Published on 2025-01-14, it carries a CVSS v3.1 base score of 8.8 (AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H) and is associated with CWE-122 and NVD-CWE-noinfo.

The vulnerability enables remote exploitation over the network with low attack complexity and no required privileges, though it necessitates user interaction. A successful attack allows an unauthenticated attacker to achieve high impacts on confidentiality, integrity, and availability, resulting in remote code execution on the targeted system.

Microsoft's update guide provides details on mitigation and patching for this vulnerability at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-21238.

Details

CWE(s)

Affected Products

microsoft
windows 10 1507
≤ 10.0.10240.20890 · ≤ 10.0.10240.20890
microsoft
windows 10 1607
≤ 10.0.14393.7699 · ≤ 10.0.14393.7699
microsoft
windows 10 1809
≤ 10.0.17763.6775 · ≤ 10.0.17763.6775
microsoft
windows 10 21h2
≤ 10.0.19044.5371
microsoft
windows 10 22h2
≤ 10.0.19045.5371
microsoft
windows 11 22h2
≤ 10.0.22621.4751
microsoft
windows 11 23h2
≤ 10.0.22631.4751
microsoft
windows 11 24h2
≤ 10.0.26100.2894
microsoft
windows server 2008
all versions, r2
microsoft
windows server 2012
all versions, r2
+5 more product configuration(s) — see NVD for full list

CVEs Like This One

CVE-2025-21417Same product: Microsoft Windows 10 1507
CVE-2025-21190Same product: Microsoft Windows 10 1507
CVE-2025-21241Same product: Microsoft Windows 10 1507
CVE-2025-21223Same product: Microsoft Windows 10 1507
CVE-2025-21236Same product: Microsoft Windows 10 1507
CVE-2025-21200Same product: Microsoft Windows 10 1507
CVE-2025-24051Same product: Microsoft Windows 10 1507
CVE-2025-21282Same product: Microsoft Windows 10 1507
CVE-2025-21306Same product: Microsoft Windows 10 1507
CVE-2025-21286Same product: Microsoft Windows 10 1507

References